Exceptionally Optimized Millimeter-Wave Properties of Cordierite-Based Materials via Innovative Processing and Predictive Analytics

This study introduces an innovative sample fabrication process aimed at optimizing the properties of Mg 2 Al 4 (Si 0.8 Ge 0.2 ) 5 O 18 cordierite ceramics. The strategic via TiO 2 -suspension, utilizes the core principles of liquid phase redistribution and particles rearrangement, to facilitate optimal densification through liquid phase sintering, thereby establishing a relationship among processing, microstructure, and material performance. The resulting composite ceramics, designated as MASG 0.2 + y wt%TiO 2 , underwent annealing, achieving an impressive near-zero temperature coefficient of frequency (TCF) of +1.99ppm/℃, a low relative permittivity (ε r ) ≤ 5.4, and a high-quality factor (Q × f ~ 106,912   GHz) at y = 4   wt.%. The microstructural analysis and Raman spectroscopy confirmed the significant influence of annealing on the dielectric properties. The novel inclusion of machine-learning predictive analytics to this work, enabled the achievement of an unprecedented near-zero TCF of -0.01ppm/℃ and a Q × f value of ~112,824   GHz (~4.3   wt% TiO 2 ), demonstrating a significant advancement in cordierite dielectrics for next-generation millimeter-wave applications.